The invention relates to process cheese and its production. More specifically, the invention relates to process cheeses with increased whey protein concentration and to methods for producing these process cheeses. This invention also relates to process cheeses having casein to whey ratios of less than about 3:1 and which retain acceptable firmness and to methods for producing these process cheeses. Generally, the process chesses of this invention have a penetrometer firmness of about 10 to about 20 mm and a softening or melting point of about 105 to about 150xc2x0 F.
Conventional processes for making natural and processed cheese essentially utilize only casein. Generally only a few percent of whey proteins are incorporated into such cheeses since the majority of whey protein is retained in the whey and discarded as a by-product of conventional cheese-making processes. Whey proteins comprise about 14 to 24 weight percent of whole or skim milk""s proteins and have a nutritional value at least comparable to that of casein. Therefore, the loss of whey proteins in conventional cheese making processes represents a costly inefficiency in these processes. The utilization of even a portion of whey proteins in the manufacture of natural and processed cheeses is of great commercial importance.
Therefore, attempts have been made to design processes which incorporate increased amounts of whey into these natural and process cheeses. However, processed cheese formulas with casein/whey protein ratios below about 3:1 give unacceptable textural characteristics (commonly expressed as xe2x80x9csoft bodyxe2x80x9d). Therefore, there remains a need for process cheeses with increased whey, which retain acceptable firmness, even with a casein to whey ratio of less than about 3:1.
Yee et al. (U.S. Pat. No. 5,750,177) describe natural cheeses with increased-whey protein having casein: whey ratios of 16:1 to 4:1 made from ultrafiltered cheese. The cheeses of Yee et al. require labor, time, and equipment-intensive ultrafiltered cheese, and result in cheese that has a whey protein:casein ratio that is no greater than that of the starting milk.
Czulak et al. (U.S. Pat. No. 4,518,616) describe methods for increasing the amount of whey protein incorporated into a natural cheese by ultra-filtering whey to form a whey protein concentrate, mixing the whey protein concentrate with milk to form an enriched milk, and then ultra-filtering the enriched milk, either before or after curding of the milk using lactic starter cultures, rennet, or combinations thereof.
The current invention provides formulations of process cheeses with casein/whey protein ratios below about 3:1 that retain a desirable firmness. The ratio of casein proteins to whey proteins in the process cheese of this invention preferably ranges from about 50:50 to about 75:25 (i.e., about 1:1 to about 3:1) as measured by gel electrophoresis. This provides major potential cost savings by allowing replacement of casein by whey proteins and/or supplementation of casein with whey proteins in a processed cheese product.
As discussed above, process cheese manufactured today generally contains only a limited amount of whey protein (i.e., less than about 25 percent whey protein relative to total protein). The current invention provides rule breaking cheeses and processes which increase the whey protein content of processed cheese (i.e., casein/whey protein ratio less than about 3:1) with controlled firmness and good melting characteristics. Generally, the process chesses of this invention have a penetrometer firmness of about 10 to about 20 mm and a softening or melting point of about 105 to about 150xc2x0 F. More preferably, the process chesses of this invention have a penetrometer firmness of about 12 to about 18 mm and a softening or melting point of about 110 to about 150xc2x0 F. Prior to this invention, increasing the whey protein to greater than about 25 percent of the total protein in process cheese could not be achieved without loss of consumer expected firmness and meltability. The current invention provides a firm, good melting process cheese having a protein composition (i.e., casein/whey protein ratio less than about 3:1) that has not previously been achieved.
The current invention provides process cheeses comprising casein and whey protein with a ratio of casein to whey protein of from about 50:50 to about 75:25. In certain preferred embodiments, the ratio of casein to whey protein in the process cheese of the current invention is from about 60:40 to about 75:25. In other preferred embodiments, the ratio of casein to whey protein is about 60:40 to about 70:30. Typically, casein is present in the process cheese of this invention at a concentration of from about 8 to about 14 percent, and whey protein is present in the process cheese of this invention at a concentration of about 4 to about 8 percent. Typically, the process cheese further comprises an emulsifier, milkfat, and may contain one or more other ingredients such as, but not limited to, whole whey, cheese, and lactic acid. In certain embodiments, an ultrafiltered cheese is not used as an ingredient in the process cheese of the current invention. The process cheese of the current invention is preferably a process cheese food or process cheese sauce in the form of a loaf, slice, or sauce.
In certain preferred embodiments, the current invention provides methods for preparing process cheese in which milk protein, whey protein, milkfat, an emulsifier, and optionally one or more other ingredients such as, but not limited to, whole whey, cheese, and lactic acid, are combined to form a dairy emulsion. The dairy emulsion is then cooked to form a cooked emulsion, and cooled to form a process cheese. The process in these preferred embodiments includes a step wherein the dairy emulsion or the cooked emulsion are homogenized. The process cheese prepared by this method has a ratio of casein to whey protein of from about 50:50 to about 75:25. In preferred embodiments, the ingredients in the dairy emulsion provide a ratio of casein to whey protein of from about 55:45 to about 65:35 in the process cheese.
In certain embodiments, the current invention provides methods for preparing process cheese in which milk protein, whey protein, milkfat, an emulsifier, and optionally one or more other ingredients such as, but not limited to, whole whey, cheese, and lactic acid, are combined to form a dairy emulsion, wherein the milk protein and/or the whey protein are a modified dairy protein source. The modified dairy protein source includes high solubility milk protein, high viscosity whey protein, emulsified high fat whey protein, and low calcium whey protein. The dairy emulsion is then cooked to form a cooked emulsion, and cooled to form a process cheese. The process cheese prepared by this method has a ratio of casein to whey protein of from about 50:50 to about 75:25. In preferred embodiments, the ingredients in the dairy emulsion provide a ratio of casein to whey protein of from about 55:45 to about 70:30 in the process cheese. Using such a modified dairy protein sources, it is not necessary to homogenize the dairy emulsion or the cooked emulsion; if desired, however, such a homogenization step can be used. In a preferred embodiment of this method, the milk protein is high solubility milk protein concentrate or isolate; most preferably for this embodiment, the ratio of casein to whey protein is from about 55:45 to about 65:35. In another preferred embodiment of this method, the milk protein is high viscosity whey protein, preferably with a low calcium concentration; most preferably for this embodiment, the ratio of casein to whey protein is from about 65:35 to about 75:25. In another preferred embodiment of this method, the milk protein is emulsified high fat protein powder; most preferably for this embodiment, the ratio of casein to whey protein is from about 55:45 to about 70:30.
In certain embodiments, the current invention includes manipulating whey protein behavior in the process cheese system by altering the mineral composition of whey protein concentrates before they are dried. Whey protein concentrate (WPC) with specific mineral content (i.e., low calcium, low magnesium, and/or high sodium) can also be used to prepare a firm processed cheese product with increased whey protein content. In a preferred embodiment of the above method, the whey protein has a low calcium concentration.
In certain embodiments, the current invention is a product produced by any of the above-described methods.